Fresh Technology For Mechanical Contractors

Commercial buildings are going green — and it’s not just new construction. Across the commercial market, demand for energy-efficient materials remains high as manufacturers work to develop products and processes that reduce a building’s overall energy consumption and stack up against stringent performance criteria.

Achrnews.com

This is just one of the four case studies included in the original full article, (link at bottom).  To me this one is the coolest of the collection.  The concept of using air curtains to block drafts from outdoors on huge trucking bays and saving thousands of dollars annually on energy costs at the same time is one of the neatest things to happen in the commercial HVAC space in a long time.   Enjoy - 

DODGING THE DRAFT

Royal Wine’s distribution center responded to employee wintertime requests for a warmer shipping area and received a bonus when six new air curtains significantly reduced operational energy costs.

ROYAL TREATMENT: In response to employee requests for a warmer shipping area in winter, Royal Wine installed Berner Industrial Direct Drive model IDC-12 air curtains with indirect gas-fired heat at the six roll-up door openings. The laminar air stream returns 70 to 80 percent of indoor energy back into the space while blocking drafts from outdoors.

Royal Wine, a global kosher winemaker, imports and produces more than 60 brands of wine, manufactures the Kedem fruit juice brand, and operates Herzog Wine Cellars with vineyards in Oxnard, California. During the winter, its distribution center in Bayonne, New Jersey, was losing thousands of dollars a year because of open shipping doors. Subfreezing temperatures near the open doors required workers to wear heavy clothing, which hampered their productivity, and caused cold air drafts regardless of portable truck and dock seals, according to Abraham Wechter, plant engineer.

Employees wanted a warmer shipping area. In response, Royal Wine decided to install air curtains on six shipping doorways.

The curtains were purchased from Berner International LLC, a U.S. manufacturer of air door/air curtain equipment. Berner is a member of the U.S. Green Building Council (USGBC), Green Building Alliance (GBA), Air Movement & Control Association (AMCA), and ASHRAE.

Royal Wine’s solution for the 8-by-10-foot roll-up door openings came in the form of six Berner Industrial Direct Drive model IDC-12 air curtains with indirect gas-fired heat. Each air curtain incorporates three ½-hp, single-speed, dual-shaft motors that drive blower wheel assemblies delivering 4,443 cfm. The resulting laminar air stream returns 70 to 80 percent of indoor energy back into the space while blocking drafts from outdoors.

Each air curtain has one 200-MBtuh indirect gas-fired unit heater, delivering a 32°F temperature rise to the air stream. Berner’s custom metal shop also attached a 14-gauge aluminized steel duct plenum transition to the air curtain inlet. Thus, the unit heater discharges heat toward the plenum, and each air curtain draws it through for uniform distribution. The heat option supplements Royal Wine’s existing unit heaters and high volume/low speed (HVLS) fans, which aid in pushing static heat down from the ceiling. The shipping area now remains at 70°, regardless of the outdoor temperature or how long the doors are open.

Each air curtain’s control package includes a factory-mounted and -wired UL listed motor control panel, complete with a rotary non-fused disconnect switch, time delay relay, a 24 V transformer, and a remote-mounted combination switch and thermostat. When the overhead roll-up doors are raised, the air curtains are activated through a 24 V floor-mounted magnetic reed switch.

Royal Wine plans to keep the air curtains activated year-round, as the plant uses several 20-ton rooftop HVAC units to maintain optimum temperatures for wine and juice storage. In addition to stable temperatures, summertime door protection will aid sanitation by keeping out dust and flying insects.

The air curtains, duct transition, and gas unit heaters were suspended from the 25-foot-high ceiling with threaded rod. Stabilization bars were used to maintain distance away from the wall, so the downward air stream isn’t obstructed by the roll-up door mechanism canister, and the air curtains were field-adjusted, so the air stream meets the floor just outside the threshold.

Consequently, employees now work in a warm, comfortable environment. Plus, per Berner’s calculations, each door reaps an annual energy savings of $3,500. Multiplying those savings by six doors totals an estimated savings of $21,000 per year.

The full article with all four case studies is here:  https://www.achrnews.com/articles/139762-case-studies-show-how-green-technology-helps-commercial-buildings